As described in Holden, H. A. and Babinsky, H. (2003) Shock/boundary layer interaction control using 3D devices In: 41st Aerospace Sciences Meeting and Exhibit, Jan. 6-9, 2003, Reno, Nev., USA, Paper no. AIAA 2003-447, as a transonic flow passes over a 3-D shock bump the supersonic local conditions induce a smeared shock foot with a lambda-like wave pattern.
Conventionally a series of such bumps is distributed across the structure with a uniform spacing.
US 2006/0060720 uses a shock control protrusion to generate a shock extending away from the lower surface of a wing.